American Kestrel (Falco sparverius)

American Kestrel

[order] FALCONIFORMES | [family] Falconidae | [latin] Falco sparverius | [authority] Linnaeus, 1758 | [UK] American Kestrel | [FR] Crecerelle d’Amerique | [DE] Buntfalke | [ES] Cernicalo chitero | [NL] Amerikaanse Torenvalk

Subspecies

Monotypic species

Genus

Members of the genus falco are mostly medium-sized falcons, but vary from the large peregrine falcon to the small American kestrel. The wings are long and pointed and used almost continuously during flight. The bill is short, powerful, and with a distinct ‘tooth’ on each side. Most falcons of this group have a black teardrop-shaped ‘mustache’ mark on each side of the head. Falcons are fastflying birds of open country and are famous for attaining high speeds as they dive from high altitudes to knock birds out of the air.

Physical charateristics

The American Kestrel is a raptor with strongly sexually dimorphic plumage. It is the smallest and most delicate-looking of the American falcons, with long wings and a long tail. Its head is blue, brown, and white. Males are brightly colored, with reddish-brown backs, slate-blue wings streaked with black, and tan breasts with black spots. The male’s head is blue and brown, and both sexes have bold, black eyespots at the napes of their necks. Females are brown streaked with black on the back, and white streaked with brown on the breast. The female has multiple bands on her tail. Both sexes have two bold, vertical face stripes.

Listen to the sound of American Kestrel

[audio:http://www.planetofbirds.com/MASTER/FALCONIFORMES/Falconidae/sounds/American Kestrel.mp3]

Copyright remark: Most sounds derived from xeno-canto

recorded by A. Bennett Hennessey


wingspan min.: 50 cm wingspan max.: 60 cm
size min.: 19 cm size max.: 21 cm
incubation min.: 29 days incubation max.: 30 days
fledging min.: 30 days fledging max.: 30 days
broods: 1   eggs min.: 3  
      eggs max.: 7  

Range

North America, Latin America : widespread

Habitat

The American kestrel nests in tree cavities, woodpecker holes, crevices of buildings, holes in banks, nest boxes or, rarely, old nests of other birds. The American kestrel is highly adaptable behaviorly and lives just about everywhere, as long as there is some open ground for hunting and conspicuous places on which to perch (e.g., telephone wires).

Reproduction

For up to six weeks before egg laying, females are promiscuous, mating with two or three males. Once a female settles with one mate, the pair mate frequently until egg laying. Three to seven eggs are laid (usually 4 or 5) over a period of 2 or 3 days. The female does most of the incubation, but males have been known to occasionally sit. Both sexes have brooding patches. Incubation lasts 29 – 30 days and hatched chicks are non-competitive. Once chicks have hatched, females beg food from males. The female, in turn, feeds the young for the first 20 days. After that period, chicks beg for food from males and feed themselves. After 30 days, chicks leave the nest. The family remains as a unit for some time. The survival rate of chicks is about 50% under natural conditions, but it is usually higher under better conditions.

Feeding habits

In the summer, American kestrels hunt in the early morning and evening, eating large insects (mainly grasshoppers). During winter, they hunt throughout daylight hours and eat small mammals (mice and sparrow-sized birds), sandpiper chicks, lizards, scorpions and amphibians.

Video American Kestrel

httpv://www.youtube.com/watch?v=Z3-CpMhmi44

copyright: Don DesJardin


Conservation

This species has a large range, with an estimated global Extent of Occurrence of 25,000,000 km2. It has a large global population estimated to be at least 4,000,000 individuals (Ferguson-Lees et al. 2001). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern.
The American kestrel permanently inhabits (without seasonal migration) North and South America from near the tree-line in Alaska and Canada and south to Tierra del Fuego. The bird can also be found in the West Indies, the Juan Fernandez Islands and Chile. It is largely absent from heavily forested areas, including Amazonia.
American Kestrel status Least Concern

Migration

Resident or sedentary over most of range. Race sparverius, from Alaska, Canada and N USA, moves S in winter: complex situation, but leap-frog migration suggested; birds from farthest N are longer range migrants; some birds move c. 2700 km, occurring S to at least Panama. Movement over water also occurs with birds from North America moving to Caribbean islands. Males tend to winter farther from areas than females. Vagrant to Falkland Is, with some birds overwintering.

Distribution map

American Kestrel distribution range map

Literature

Title Sex-related differences in habitat selection in wintering American kestrels,
Falco sparverius
Author(s): DANIEL R. ARDIA and KEITH L. BILDSTEIN
Abstract: The American kestrel, Falco sparverius, has sex-re..[more]..
Source: Anim. Behav., 1997, 53, 1305-1311

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Title Possible relationships between morphology, territory
quality, and skin color of American Kestrels
Author(s): Mark R. Bostrom and Gary Ritchison
Abstract: Carotenoid-based coloration of skin and plumage ha..[more]..
Source: J. Field Ornithol. 77(4):392-398, 2006

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Title Copulatory behaviour and paternity in the American kestrel:
the adaptive significance of frequent copulations
Author(s): M. VILLARROEL, D. M. BIRD and U. KUHNLEIN
Abstract: The adaptive significance of repeated withinpair c..[more]..
Source: ANIMAL BEHAVIOUR, 1998, 56, 289-299

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Title Regulation of Yolk-Androgen Concentrations by
Plasma Prolactin in the American Kestrel
Author(s): Keith W. Sockman, Hubert Schwabl, and Peter J. Sharp
Abstract: The concentrations of maternally derived androgens..[more]..
Source: Hormones and Behavior 40, 462-471 (2001)

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Title ISOLATION OF A HERPESVIRUS FROM AN AMERICAN
KESTREL WITH INCLUSION BODY DISEASE
Author(s): L N. D. POTGIETER
Abstract: A herpesvirus was isolated from the liver of a cap..[more]..
Source: Journal of Wildlife Diseases Vol. 15, January, 1979

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Title Conservation Assessment for the American Kestrel in the Black Hills National Forest, South Dakota and Wyoming.
Author(s): Aran S. Johnson and Stanley H. Anderson
Abstract: This report assesses the biology and conservation ..[more]..
Source: Wyoming Cooperative Fish and Wildlife Research Unit

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Title American Kestrel Use of Pine Regeneration Stands in South Carolina
Author(s): Amanda Allen Beheler and John B. Dunning, Jr.
Abstract: The American Kestrel (Falco sparverius) is widely ..[more]..
Source: Department of Forestry and Natural Resources. Purdue University

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Title EASTERN SCREECH-OWL HATCHES AN AMERICAN KESTREL
Author(s): TIMOTHY F. BREEN AND JOHN W. PARRISH JR.
Abstract: An Eastern Screech-Owl (Otus asio) was found incub..[more]..
Source: J. Field Ornithol., 67(4):612-613

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Title Reverse mounting in the American Kestrel.
Author(s): REED BOWMAN AND ELIZABETH M. CURLEY
Abstract: Reverse mounting during mating has been reported i..[more]..
Source: Wilson Bull., 98(3), 1986, pp. 412-473

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Title Plasma corticosterone in American kestrel siblings: effects of age,
hatching order, and hatching asynchrony
Author(s): Oliver P. Love, David M. Bird, and Laird J. Shutt
Abstract: Although it is well documented that hatching async..[more]..
Source: Hormones and Behavior 43 (2003) 480-488

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Title ECOLOGICAL CORRELATES OF MATE REPLACEMENT IN THE
AMERICAN KESTREL
Author(s): REED BOWMAN AND DAVID M. BIRD
Abstract: During 1983 and 1984 one adult member of 20 pairs ..[more]..
Source: The Condor 88:440-445

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Title Haemoproteus tinnunculus in the American Kestrel (Falco sparverius)
Author(s): P. J. Maloney
Abstract: Unspecified species of Haemoproteus have been reco..[more]..
Source: Journal of Wildlife Diseases, 20(1), 1984, pp 57-58

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Title Misdirected incubation in American Kestrels: a case of competition for nest sites?
Author(s): RUSSELL D. DAWSON AND GARY R. BORTOLOTTI
Abstract: Reports of birds exhibiting unusual incubation beh..[more]..
Source: Wilson Bull., 109(4), 1997, pp. 732-734

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Title Study Plan for Avian Injury Study
Author(s): unknown
Abstract: Past and continuing discharges of polychlorinated ..[more]..
Source: HUDSON RIVER NATURAL RESOURCE TRUSTEES

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Title Size dimorphism in mated pairs of American Kestrels
Author(s): REED BOWMAN
Abstract: The degree of dimorphism between males and females..[more]..
Source: Wilson Bull., 99(3), 1987, pp. 465-467

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Title Hypothermic tolerance in an embryonic
American kestrel (Falco sparverius)
Author(s): Keith W. Sockman and Hubert Schwabl
Abstract: Embryos of several bird species tolerate acute hyp..[more]..
Source: Can. J. Zool. 76: 1399-1402 (1998)

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Title The effects of temperature and artificial rain on the metabolism of
American kestrels (Falco sparverius)
Author(s): Glenn R. Wilson, Sheldon J. Cooper, James A. Gessaman
Abstract: The effect of rainfall on the metabolism of birds ..[more]..
Source: Comparative Biochemistry and Physiology, Part A 139 (2004) 389- 394

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Title Carotenoid concentration and coloration of American
Kestrels (Falco sparverius) disrupted by experimental
exposure to PCBs
Author(s): GARY R. BORTOLOTTI et al.
Abstract: Bright coloration in birds is typically a sexually..[more]..
Source: Functional Ecology 2003 17, 651-657

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Title VOCAL DEVELOPMENT IN AMERICAN KESTREL (FALCO SPAR VERIUS) NESTLINGS
Author(s): JOHN A. SMALLWOOD et al.
Abstract: We studied the acoustical characteristics of calls..[more]..
Source: j. Raptor Res. 37(1):37-43

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Title Nest Success of Southeastern American Kestrels
Associated with Red-Cockaded Woodpeckers in
Old-Growth Longleaf Pine Habitat in Northwest Florida
Author(s): KATHLEEN E. GAULT et al.
Abstract: The Southeastern American Kestrel (Falco sparveriu..[more]..
Source: SOUTHEASTERN NATURALIST 3(2):191-204

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Title Capture Rate of American Kestrel During Nonbreeding
Season Influenced by Sex of Bird in
Upstate South Carolina
Author(s): Samuel H. deMent and Reed S. deMent
Abstract: Assuming equal distribution of male and female Ame..[more]..
Source: The Chat, Vol. 65, No.3, Summer 2001

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